Provider
- University of California Berkeley848
- GMU518
- University of Maryland505
- University of Nebraska-Lincoln468
- The Ohio State University256
- Northwestern University252
- Purdue University233
- BTAA-GIN98
- Baruch CUNY82
- University of Chicago70
- University of Nevada, Reno12
- Cornell7
- GeoBlacklight Community2
- MIT1
- U.S. Geological Survey, Department of the Interior1
- University of Indiana1
- Wisconsin State Cartographer's Office1